this is probably an easy fix but I have this problem with a few skins for M4 and V4 . 

as you can see along the side of the ear and where the two skin pieces meet around the body I have white lines showing. how can I stop this please? 

I haven't seen this issue in years, and in the past, the solution was to extend the diffuse texture map beyond the UV borders. If you are using grayscale texture maps for bump, displacement, specular, etc., check that their gamma values are set to 1. 

Is it a question of making sure the skinning is Poser Unimesh?

(Figure/Skinning Method/Poser Unimesh)

For me at least, I get lines on the texture if it is set to Poser Traditional.

Is it a question of making sure the skinning is Poser Unimesh?

(Figure/Skinning Method/Poser Unimesh)

For me at least, I get lines on the texture if it is set to Poser Traditional.

Is this a render or a preview? If it's a render, which render engine are you using?

Those are showing right at the edges of the texture. The face texture map ends right in front of the ears like that. And you say this only affects some textures. I think the texture map just isn't painted all the way to the edge. The solution would be to extend the edges of the face texture, like hborre said.

The lines we used to get from not picking unimesh were cleaner than this, I don't think it's that. (I think it's still a good idea to pick unimesh skinning, I just don't think that's the cause of this specific issue.)

well thank for all of the feedback peeps.

this is a full render pic and I  use firefly . I looked and I don't see where gamma values is but their are no extra bump maps or other textures used with this skin. I use this for my comic so i need to be sure it looks right. I think I will try to extend the skin map areas on the texture. 

On V4's and M4's, the white line is precisely on the limit between the face material ("1_SkinFace") and the ear+head ("2_SkinHHead").
I have seen such weird effect once, on a Vic4, near the nose flesh and I had to change the parameters to get around this.

From what I could understand, it's as if some parts are intersecting with one another. Maybe try giving another scattergroup id to one part, to see if that forces Poser to avoid that not desired intersection by setting the order in which the skin parts are computed.